Better typings for promise.race based on conditional types (#31117)

Following the feature - Mapped tuple types #25947 - it is now possible to have better typings for Promise.race
microsoft · Apr 30, 2019 · d102ec0 · d102ec0
1 parent 90d3acf
commit d102ec0
Showing 1 changed file with 3 additions and 67 deletions.
diff --git a/src/lib/es2015.promise.d.ts b/src/lib/es2015.promise.d.ts
@@ -98,79 +98,15 @@ interface PromiseConstructor {
      * @param values An array of Promises.
      * @returns A new Promise.
      */
-    race<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>(values: [T1 | PromiseLike<T1>, T2 | PromiseLike<T2>, T3 | PromiseLike<T3>, T4 | PromiseLike<T4>, T5 | PromiseLike<T5>, T6 | PromiseLike<T6>, T7 | PromiseLike<T7>, T8 | PromiseLike<T8>, T9 | PromiseLike<T9>, T10 | PromiseLike<T10>]): Promise<T1 | T2 | T3 | T4 | T5 | T6 | T7 | T8 | T9 | T10>;
+    race<T>(values: T[]): Promise<T extends PromiseLike<infer U> ? U : T>;
 
     /**
      * Creates a Promise that is resolved or rejected when any of the provided Promises are resolved
      * or rejected.
-     * @param values An array of Promises.
-     * @returns A new Promise.
-     */
-    race<T1, T2, T3, T4, T5, T6, T7, T8, T9>(values: [T1 | PromiseLike<T1>, T2 | PromiseLike<T2>, T3 | PromiseLike<T3>, T4 | PromiseLike<T4>, T5 | PromiseLike<T5>, T6 | PromiseLike<T6>, T7 | PromiseLike<T7>, T8 | PromiseLike<T8>, T9 | PromiseLike<T9>]): Promise<T1 | T2 | T3 | T4 | T5 | T6 | T7 | T8 | T9>;
-
-    /**
-     * Creates a Promise that is resolved or rejected when any of the provided Promises are resolved
-     * or rejected.
-     * @param values An array of Promises.
-     * @returns A new Promise.
-     */
-    race<T1, T2, T3, T4, T5, T6, T7, T8>(values: [T1 | PromiseLike<T1>, T2 | PromiseLike<T2>, T3 | PromiseLike<T3>, T4 | PromiseLike<T4>, T5 | PromiseLike<T5>, T6 | PromiseLike<T6>, T7 | PromiseLike<T7>, T8 | PromiseLike<T8>]): Promise<T1 | T2 | T3 | T4 | T5 | T6 | T7 | T8>;
-
-    /**
-     * Creates a Promise that is resolved or rejected when any of the provided Promises are resolved
-     * or rejected.
-     * @param values An array of Promises.
-     * @returns A new Promise.
-     */
-    race<T1, T2, T3, T4, T5, T6, T7>(values: [T1 | PromiseLike<T1>, T2 | PromiseLike<T2>, T3 | PromiseLike<T3>, T4 | PromiseLike<T4>, T5 | PromiseLike<T5>, T6 | PromiseLike<T6>, T7 | PromiseLike<T7>]): Promise<T1 | T2 | T3 | T4 | T5 | T6 | T7>;
-
-    /**
-     * Creates a Promise that is resolved or rejected when any of the provided Promises are resolved
-     * or rejected.
-     * @param values An array of Promises.
-     * @returns A new Promise.
-     */
-    race<T1, T2, T3, T4, T5, T6>(values: [T1 | PromiseLike<T1>, T2 | PromiseLike<T2>, T3 | PromiseLike<T3>, T4 | PromiseLike<T4>, T5 | PromiseLike<T5>, T6 | PromiseLike<T6>]): Promise<T1 | T2 | T3 | T4 | T5 | T6>;
-
-    /**
-     * Creates a Promise that is resolved or rejected when any of the provided Promises are resolved
-     * or rejected.
-     * @param values An array of Promises.
-     * @returns A new Promise.
-     */
-    race<T1, T2, T3, T4, T5>(values: [T1 | PromiseLike<T1>, T2 | PromiseLike<T2>, T3 | PromiseLike<T3>, T4 | PromiseLike<T4>, T5 | PromiseLike<T5>]): Promise<T1 | T2 | T3 | T4 | T5>;
-
-    /**
-     * Creates a Promise that is resolved or rejected when any of the provided Promises are resolved
-     * or rejected.
-     * @param values An array of Promises.
-     * @returns A new Promise.
-     */
-    race<T1, T2, T3, T4>(values: [T1 | PromiseLike<T1>, T2 | PromiseLike<T2>, T3 | PromiseLike<T3>, T4 | PromiseLike<T4>]): Promise<T1 | T2 | T3 | T4>;
-
-    /**
-     * Creates a Promise that is resolved or rejected when any of the provided Promises are resolved
-     * or rejected.
-     * @param values An array of Promises.
-     * @returns A new Promise.
-     */
-    race<T1, T2, T3>(values: [T1 | PromiseLike<T1>, T2 | PromiseLike<T2>, T3 | PromiseLike<T3>]): Promise<T1 | T2 | T3>;
-
-    /**
-     * Creates a Promise that is resolved or rejected when any of the provided Promises are resolved
-     * or rejected.
-     * @param values An array of Promises.
-     * @returns A new Promise.
-     */
-    race<T1, T2>(values: [T1 | PromiseLike<T1>, T2 | PromiseLike<T2>]): Promise<T1 | T2>;
-
-    /**
-     * Creates a Promise that is resolved or rejected when any of the provided Promises are resolved
-     * or rejected.
-     * @param values An array of Promises.
+     * @param values An iterable of Promises.
      * @returns A new Promise.
      */
-    race<T>(values: (T | PromiseLike<T>)[]): Promise<T>;
+    race<T>(values: Iterable<T>): Promise<T extends PromiseLike<infer U> ? U : T>;
 
     /**
      * Creates a new rejected promise for the provided reason.